Various embodiments described generally relate to safety systems at work sites, and in particular to a proximity detection system and methods of adjusting an electromagnetic filed produced by the same.
Many methods have been devised to protect people from being struck, pinched, crushed or otherwise harmed by vehicles and mobile equipment used for above and below ground operations. Examples of the equipment include: road construction equipment such as trucks, road graders, rollers and pavers; surface mining equipment, such as for use with gravel and sand operations, front end loaders, trucks, dozers, conveyors and other items; underground mining equipment such as continuous miners, shuttle cars, conveyors, crushers, load-haul-dump vehicles, man-trips, tractors; and other equipment such as fork lifts, cranes, and trucks used at warehouses and shipping ports.
A number of different proximity detection systems have been devised to protect people and property in these industrial operations, such as the systems disclosed in U.S. Patent Application Publication No. 2006/0087443, and U.S. Pat. Nos. 6,810,353 and 5,939,986, which are incorporated by reference herein in their entirety. These proximity detection systems establish a warning zone around dangerous equipment or areas by generating a magnetic field perimeter. A worker who enters the magnetic field perimeter carrying a magnetic field detection device is warned of his or her presence within the magnetic field perimeter and his or her corresponding proximity to the dangerous vehicle. To maintain a warning zone of an appropriate size, the proximity detection systems may be calibrated or otherwise optimized at a factory or laboratory before installing the system in the field.
However, industrial environments involve a wide range of climatic and environmental conditions that may cause a proximity detection system to perform differently under field conditions compared to the controlled conditions in a laboratory or factory. In some cases, the size of the magnetic filed perimeter created by the proximity detection system in the field may be significantly different from the size of the perimeter created under ideal conditions. Therefore, there is a need to be able to adjust a proximity detection system at the time of installation, or thereafter, to optimize performance and/or to calibrate the system to the desired operational settings.